Impact of machined versus structured implant shoulder designs on crestal bone level changes: a randomized, controlled, multicenter study

Int J Implant Dent. 2022 Jul 16;8(1):31. doi: 10.1186/s40729-022-00432-4.

Abstract

Purpose: The collar region of an implant is its connection to the oral cavity. A balance between osseointegration on one hand and the absence of plaque accumulation on the other hand is necessary for successful implantation. It is yet to be determined which implant collar design, polished or rough, is best to stabilize the crestal bone level, avoiding peri-implantitis and subsequent risk of implant loss. The aim of this study was to investigate the influence of the architecture of the collar region on marginal bone and soft tissue response.

Methods: This prospective, randomized, clinically controlled multicenter study included 58 patients undergoing dental implant treatment using a pair of dental implants with either machined or rough-surfaced shoulder regions. Patients were clinically and radiologically examined for bone level height and signs of inflammation after 6, 12 and 24 months.

Results: No implant was lost within the 2 years of follow-up (100% survival rate). No significant differences on crestal bone loss (machined neck: 0.61 mm ± 0.28 mm, rough neck 0.58 mm ± 0.24 mm) and on soft tissue response (probing depth 3-6 mm with bleeding on probing 7.6% in machined-neck implants and in 8.3% in rough neck implants) were observed between implants with machined and roughened neck after 2 years.

Conclusions: Machined and roughened neck implants achieved equally good results concerning peri-implant bone loss, the rate of peri-implantitis and implant survival rate/hard and soft tissue integration. None of the two collar designs showed a clear advantage in peri-implant reaction. Trial registration German Clinical Trials Register, DKRS00029033. Registered 09 May 2022-Retrospectively registered, http://www.dkrs.de.

Keywords: Implant design; Machined vs. rough implant collar; Peri-implant bone level; Peri-implantitis.

Publication types

  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alveolar Bone Loss* / etiology
  • Dental Implantation, Endosseous / adverse effects
  • Dental Implants* / adverse effects
  • Dental Prosthesis Design / adverse effects
  • Humans
  • Peri-Implantitis* / chemically induced
  • Prospective Studies
  • Shoulder
  • Surface Properties

Substances

  • Dental Implants